Search results for " Contamination"
showing 10 items of 571 documents
Sensitive Monoclonal Antibody-Based Immunoassays for Kresoxim-methyl Analysis in QuEChERS-Based Food Extracts
2014
Kresoxim-methyl is nowadays widely used to combat a diversity of common diseases affecting high-value crops. In this article, we report the development and characterization of two novel immunoassays for the analysis of this pioneer strobilurin fungicide, and for the first time, a validation study with food samples was performed. A direct and an indirect competitive immunoassay based on a new anti-kresoxim-methyl monoclonal antibody were developed for sensitive and specific chemical analysis. Optimized assays showed limits of detection of 0.1 μg/L. Fruit and vegetable samples were extracted with acetonitrile by the QuEChERS procedure and analyzed by the developed immunoassays after a simple …
Determination of five pesticide residues in oranges by matrix solid-phase dispersion and liquid chromatography to estimate daily intake of consumers.
2001
Abstract Residues of benzoylphenylurea insecticides (diflubenzuron, hexaflumuron, and flufenuxuron), carboxamide acaricides (hexythiazox), and carbamate insecticides (benfuracarb) were determined in 150 orange fruit samples from September 1998 to June 1999, to estimate exposure of the Valencian population to oranges contaminated with these newly developed pesticides. The method for monitoring these residues is based on matrix solid-phase dispersion and liquid chromatography with UV or atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) detection. Orange samples representing 11 varieties were collected from an agricultural cooperative and examined for the 5 pesticides. In 74…
Rapid differentiation of commercial juices and blends by using sugar profiles obtained by capillary zone electrophoresis with indirect UV detection.
2015
A method for the determination of sugars in several fruit juices and nectars by capillary zone electrophoresis with indirect UV-vis detection has been developed. Under optimal conditions, commercial fruit juices and nectars from several fruits were analyzed, and the sugar and cyclamate contents were quantified in less than 6 min. A study for the detection of blends of high-value juices (orange and pineapple) with cheaper alternatives was also developed. For this purpose, different chemometric techniques, based on sugar content ratios, were applied. Linear discriminant analysis showed that fruit juices can be distinguished according to the fruit type, juice blends also being differentiated. …
Use of polarography as a quality-control method for determining diacetyl in citrus and vegetable juices, yoghurt and butter
2002
The determination of diacetyl permits the detection of microbial growth in the processing of citrus fruit before the appearance of other organoleptic, chemical or microbiological changes. It also makes it possible to detect a break in the cold chain during distribution and sale. The study proposed a polarographic method for the determination of diacetyl that allowed routine analysis with the aim of detecting possible contamination in the citrus juice manufacturing chain (orange and orange-carrot). The analytical performance of the method in terms of a linearity from 0 to 960 microg ml(-1), a recovery of 97 to 98%, a precision of 3.2 to 4.8%, and a sensitivity of 0.2 ng ml(-1) for juices ind…
A 21st century technique for food control: electronic noses.
2008
This work examines the main features of modern electronic noses (e-noses) and their most important applications in food control in this new century. The three components of an electronic nose (sample handling system, detection system, and data processing system) are described. Special attention is devoted to the promising mass spectrometry based e-noses, due to their advantages over the more classical gas sensors. Applications described include process monitoring, shelf-life investigation, freshness evaluation, authenticity assessment, as well as other general aspects of the utilization of electronic noses in food control. Finally, some interesting remarks concerning the strengths and weakn…
Assessment of polycyclic aromatic hydrocarbons (PAHs) in soil of a Natural Reserve (Isola delle Femmine) (Italy) located in front of a plant for the …
2009
Isola delle Femmine Natural Reserve is a very little isle about 15 km from the centre of Palermo, in front of a plant for the production of cement and about 600 m from coast. In the present research, profiles soil PAHs were obtained for 16 sites within the reserve and for 8 stations on the rural soil taken as reference. summation Sigma PAHs, in the soil of investigated area, ranged from 35 to 545 microg/kg. With the aim to find the origin of PAHs in the soil of Isola delle Femmine, we compare the distribution of single analytes in the investigated area with those of the reference rural area (Monte Raffo Rosso), with those of atmospheric urban particulate collected at Palermo along with repo…
Pressurized liquid extraction combined with capillary electrophoresis–mass spectrometry as an improved methodology for the determination of sulfonami…
2007
A new analytical method, based on capillary electrophoresis and tandem mass spectrometry (CE-MS2), is proposed and validated for the identification and simultaneous quantification of 12 sulfonamides (SAs) in pork meat. The studied SAs include sulfathiazole, sulfadiazine, sulfamethoxypyridazine, sulfaguanidine, sulfanilamide, sulfadimethoxyne, sulfapyridine, sulfachloropyridazine, sulfisoxazole, sulfasalazine, sulfabenzamide and sulfadimidine. Different parameters (i.e. separation buffer, sheath liquid, electrospray conditions) were optimized to obtain an adequate CE separation and high MS sensitivity. MS2 experiments using an ion trap as analyzer, operating in the selected reaction monitori…
Absence Ochratoxin A in soy sauce
2004
A method is described for the determination of ochratoxin A (OTA) in soy sauce using phosphate-buffered saline (PBS) extraction, an immunoaffinity clean-up, a liquid chromatographic determination with fluorescence detection (LC-FD) and confirmation with LC-FD after methylation of OTA. Recoveries of OTA spiked to soy sauce samples at 0.25 ng/ml level were 90% with relative standard deviations of 4%. The limit of detection was 0.01 ng/ml for OTA using the proposed method. Furthermore, the proposed method was applied to 60 soy sauce samples from China and Japan and none of them were found to contain OTA.
Risk factors for gastroenteritis associated with canal swimming in two cities in the Netherlands during the summer of 2015: A prospective study
2017
Urban canal swimming events are popular in the Netherlands. In 2015, two city canal swimming events took place, in Utrecht (Utrecht Singel Swim, USS) and in Amsterdam (Amsterdam City Swim, ACS). This prospective study characterizes the health risks associated with swimming in urban waters. Online questionnaires were sent to 160 (USS) and 2,692 (ACS) participants, with relatives of participants who did not swim completing the questionnaire as a control. Swimming water specimens and stool specimens of diarrheic participants in the ACS group were analysed. A total of 49% of USS and 51% of ACS swimmers returned their questionnaires. Nine percent of USS swimmers and 4% of non-swimmers reported g…
A practical and transferable methodology for dose estimation in irradiated spices, based on thermoluminescence dosimetry
2008
Abstract The thermoluminescence technique is recommended by the European Committee for Standardization for the detection of irradiated food containing silicates as contaminants. In this work, the applicability of the thermoluminescence technique as a quantitative method to assess the original dose in irradiated oregano was studied; the additive-dose method was used, with reirradiation doses up to 600 Gy. The proposed new procedure allows to clearly discriminate irradiated from unirradiated samples, even after one year storage, and it gives an acceptable estimation of the original dose; the overall modified procedure requires only one day to be completed.